How to Conceive a Demon
by aSouthernCharmer
Summary: When Yukio tells Rin more about their mother, Rin gets even more curious of how she became their mother. How can a demon reproduce anyway? Especially when the father has no body? Warning: A/B/O dynamics, incest, and yaoi.


05/22/2018

 _Warning! This is a_ _ **Yukio x Rin**_ _story! Which means there will be incest, A/B/O dynamics, sex, and incest! Don't like? Don't read!_

 _Summary: When Yukio tells Rin more about their mother, Rin gets even more curious of how she became their mother. How can a demon reproduce anyway?_

Cold, white snow fell around us as we traveled out further into the woods. A soft crunching noise could be heard under our feet. I glanced behind me to see an old, fallen in shack that seemed to be stranded out in the middle of nowhere.

Yukio had taken one of those magical keys that seemed to defy the laws of time and space. He had simply said he just had a surprise for me, so I really had no clue where we are going. I just loyally followed him, leading up to where we are now.

As I watched him walking slightly in front of me, I looked at my brother's new body. It was odd, really, seeing Yukio with this servant-like tail swaying behind him as he walked, pointed ears, and fangs that matched my own. While these similarities does make us look more like the twins we actually are, it also sets us apart in more ways than before.

I would say we are like Yin and Yang. Yukio is the good guy. He has spent the majority of his life looking after his "older" brother. He is the smart one, the one girls chased after, and he was frankly the better brother. He is taller, more built, and had better manners. Those teal eyes, smooth skin, and brown hair made him look angelic.

Me on the other hand… I am the punk. The one who can't keep a job and fail most all my classes. I have no talents or skills. My sharp violet blue eyes, shaggy navy hair, and scrawny body made me look more like the demon that I actually am.

I'm not really a good brother to Yukio. Yeah, as a little kid I stood up to the bullies for him, but at some point the roles became reversed. One day, I was the one protecting him, and the next day he was protecting me. It happened somewhere between me awaking my demon and him becoming an exorcist, I'm sure.

For an example, like now, I am following around my brother, clueless. He made the decision for us to go out here for some reason, and I just let him led the way with no questions asked. Even now he had this protective demeanor about him. Even though I had learned control of my flames, he still didn't trust others around us or me.

Yukio has become even more mature since he awakened his blue flames. After all, our own birth father, Satan, had said that he wanted Yukio's body over mine because of that very reason. He had natural skill and talent. He was able to harness is power in a fraction of the time it took me. It just shows how incredible Yukio is, and why he is the better brother.

So lost in my own thoughts, I did not know when Yukio stopped until I ran into him.

"We are here." He said.

I looked around him to see this small cave that was filled in with rocks and flowers all around. It was strange to see the beautiful array in the middle of all this snow. After all, flowers aren't in season right now.

Yukio continued to walk ahead until he squatted near the cave. He used his hands to push aside a mound of snow. I came up beside him and squatted as well to see what he was digging for. My tail wagged in a curious manner behind me.

"Here it is." Yukio whispered. I looked down to see what he uncovered. There was a square, flat rock that read the name Yuri Egin. Was this a grave? Why did Yukio bring me here? Before I had time to ask, Yukio cleared his throat. "When Satan possessed my body, I had a chance to glance through his memories, and in those memories I got the chance to see the women who carried and gave birth to us. It was on a snowy day like this. While it seems impossible to understand, I could fell the deep pain and longing Satan had for this woman named Yuri. I could tell he loved her. And if the memories were true, it seemed that she loved him too."

"Yukio, so this is our mother's grave?" I asked before biting my lip in nervousness.

"Yes. She died shortly after we were born. After we fought to close the gates of hell, I had a hard time coping with my new body and Satan's memories. I actually approached Mephisto, seeing as he was once one of the Kings in hell. Him and dad actually found us out here sometime shortly after we were born." Yukio said, staring at the rock engraved with our birth mother's name below him. His face was impassive.

"Did you see what she looked like… in those memories?" I asked. I had always imagined what she must have looked like. If one of us favored her more than the other, took after her more in our personality, what she was like…

"Yeah… It is funny to say we took after her in different ways. From what I could tell, she had long brown, curly hair with teal blue eyes. She had moles that complimented each of her eyes. She was so full of life and curious about the world around her. She was passionate about living in a world of peace between humans and demons. But before she became our mother, she was a strong and powerful exorcist." Yukio replied. His eyes sparkled with love and his cheeks grew flush as he spoke of her.

I could imagine that Yukio got his looks from her, whereas it seemed that I got her fiery personality. I let my imagination wonder. I could visualize the women Yukio described. The shape of my eyes really seems like the only physical attribute I gained from her. While Satan doesn't have a human body, I can't help but wonder if I look more like he would if he had one? As this subject was going deeper than I would like to imagine, I shock my head to get out of those thoughts and looked back at Yukio.

"Thank you, Yukio, for sharing this with me. I feel so… happy now that I can finally know who our mother was." I said with wide toothy grin plastered on my face.

Yukio turned toward me slowly. I could see that he was having some sort of internal battle by looking into his eyes. But just as quickly as I saw it, he blinked it away and stood up. I followed suit as he started to retreat back to the shack we came from.

"That cabin is where she spent all of her time after running away from the Order. She made friends with the demons in this forest, which is why there are flowers on her grave. That is something you gained from her, Rin. You were always able to see the good in demons, while I felt that all of them were our enemy." He said as he stepped inside the wooden shed that no longer could provide much protection from the harsh weather.

We looked around the place once inside. It was less than 500 square feet, and had just enough room for a place to cook and a place to sleep. It seemed as if she only stayed here when necessary. My thoughts were interrupted as Yukio spoke again, "That cave that we saw earlier, the one that was fallen in? That is where she gave birth to us. Mephisto told me that him and father found us in her arms lying on an oversized pillow. She had named the one without flames Yukio and the one with flames Rin. She had died shortly after they had gotten there from the childbirth. They both had intended to kill her and the spawn of Satan. But when father had raised the sword, you had smiled at him, and he couldn't follow through on his orders. That is when he sealed away your powers in the sword. He had made a vow to raise us as human kids and give us a normal life. That means it was you who saved us from death, Rin." Yukio turned to look at me. He had this look of deep apathy and love in his eyes. I rubbed the back of my head nervously.

"Yeah, our dad was pretty awesome like that. It is kind of silly, really, that the spawn of Satan were raised by one of the most powerful exorcists on earth, who are now training to become exorcist as well." I laughed at the irony.

I am aware that Yukio had a difficult time coping with his transition. He went from a normal human to a demon in practically one day. He had been perfect in every way possible, and I could tell that he felt his life was ruined in someway now because of our genetics. The Order had buckled down on Yukio's "privileges", which pissed me off since we are the ones who saved his world from our own biological father, Satan. But, it is human nature for them to fear the things they don't understand. Hell, I don't even completely understand our situation truthfully.

Speaking of not understanding, I felt myself blush as I moved on to my next question. "Hey, Yukio? Umm… did you happen to see the memory of, well… How did mom exactly get, you know… pregnant anyway? Since Satan couldn't have, um, a body?" I stuttered out of embarrassment, but no less curious.

Yukio seemed to be taken aback and surprised with the sudden personal question. His cheeks were dusted red all the way up to the tip of his ears. "Oh God, Rin. No I didn't see that sort of memory, nor did I want to. I just know that Satan grew fond of mom after he tried to possess her and saw that she was immune to his blue flames."

"So… is it because of the blue flames that she got pregnant?" I asked, trying to make sense of this in my head. The whole demon love or reproduction always baffled me.

"I don't know, Rin. It doesn't really matter now." He said. I wanted to disagree, but I fell silent and drifted back to my own thoughts. I could tell he was avoiding my questions, and me just because I probably know Yukio better than anyone else. We are twins, after all.

I started playing with my own blue flame on the tip of my finger, studying it. I watched it flicker and thought about how much misery they have brought the world. If our mother was immune to these flames, did that mean she could be consumed in them without anything bad happening to her? Did that mean that Satan couldn't possess her?

I suddenly felt a strong chest against my back before a hand came up to meet mine. Yukio ignited his flame with my own, creating an even more bright blue light. "They said it themselves, brother, that we are stronger together. Our flames and our blood can agree to that. Since I have become a demon, I can feel my instincts telling me to stay close to you always. Hell, we are the spawn of Satan, so we are a walking, talking sin. What could be worse than that?" He said quietly into my pointed ear. Suddenly, that same mouth that whispered into my ear let out its slick tongue to lick and nip at it.

I knew all too well what Yukio was feeling. It was as if my blood screamed to follow Yukio and be next to him at all times. I had approached Bon about if he knew anything about demon mating or anything like that, because it would be too awkward to ask my brother. He had blushed and told me what little he knew. Apparently, demons are more like animals than I had thought.

Demons can have alphas, betas, and omegas, just like animals. While he wasn't sure about how they reproduce, he did know that a lot of incest and other "sins" was the way most demons lived by and did things. So it explained the nature of the feelings I had toward Yukio, and by the looks of it they way he feels about me as well.

His hands went from my own to my waist, pulling up my shirt enough to explore my chest. I gasped as his mouth moved down to my neck. I couldn't help but moan out his name when he used his fangs to bite my neck. I felt a sucking motion, which left me a squirming mess against him. My hips grinded backwards, and it allowed me to feel just how much my brother wanted me.

"Your blood is sweeter than any candy I have ever tasted. It sings for me, Rin." He said as he detached himself from me. I was left hot all over and my breath coming out in pants. That one bite was all it took for me to have this level of want and desire. I wanted more.

Yukio suddenly stood up. I groaned at the lost of contact before I was picked up bridal style and that hot mouth was next to my ear again. "Shhh… Let me take you somewhere more… appropriate."

I did not completely know what he was talking about. My mind was hazed over with yearning. I felt him walking as I buried my face in Yukio's neck, inhaling the intoxicating scent that is my little brother. I guess my loaded question about our conception had his mind rolling to suddenly act like this. But I have to agree, this sin can't be any worse than being the children of Satan.

Before I knew it, I was dropped down on a soft surface. I looked up to see Yukio with a soft smile on his face. While I did not have a clue about my own status in the demon-mating world, I had no doubt that Yukio is an alpha in that moment.

"Now we can be comfortable and won't be bothered by anyone." He said as he put away his keys and locked the door to our dorm room. Thankfully, we had the whole dormitory to ourselves, so I knew we didn't have to hold back.

I circled my arms around Yukio's neck as he joined me back on the bed. His knee fell in between my legs, grinding slightly up against my groin. I gasped and pulled him down to meet my lips. It was the first kiss we have ever shared. We battled for dominance with our tongues, and obviously I loss pretty quickly. I gave into his biting and sucking. Our tongues swirled together like a dance, and it made my clothes feel like they were too tight.

I heard Yukio chuckle as he pulled away from our kiss. A small sting of salvia connected us as proof of our act. "That is a good look on you, brother." He said with a lustful, raspy voice. I could feel my face grow hot. I looked down at how disheveled my clothes was. My lips were already swollen and wet form the exchange of salvia. I'm sure I looked like the model for the word "lewd".

My eyes were trained on Yukio. How his cheeks were rosy in a girly way, but his body demanded to have me submit underneath it. His muscles were taunt and hard underneath his white button-up shirt. It was stuck to him like a second skin with all the sweat, allowing me to see all the outlines of his body. I reached out and grabbed the shirt, attempted to unbutton it with no sense of patience.

"What is it, Rin? Do you want me to strip?" He said with a cocky smile.

"P-please, brother. I wanna feel." I said, begging.

Yukio withdrew from his position over me, and I went to grab him, but he slapped my hand away before I could. "Be good for me, Rin, and you will get what you want." I groaned but nodded my head in submission.

He went over to his desk, digging around for something I couldn't see before returning to the end of the bed. I could see him perfectly in the moonlight. He slipped off his glasses, placing them on the nightstand nearby first. Next he placed a hand on his hip with his tail curled around it that helped give off the dominant aura he now possessed so fiercely.

"Rin, if you want to feel this," he said as his hand traces his clothed chest, "You must do as I say, okay?"

I nodded my head in understanding.

"No, Rin. You have to talk to me."

"Okay… I understand." I said as I squirmed in the bed again in need. I didn't really like this game, but I felt the overwhelming need to please him, so he would touch me sooner.

"Good. Now first I want you to take off your clothes… all of them."

"Yes… sir." I said. I quickly stripped out of all my clothes, pulling my shirt off first then removing my pants and underwear together in one swift motion. When I was done, my hands settled on top of my member to give myself a little bit of dignity.

"Remove your hands, brother. I want to see you… all of you." Yukio said. His voice was dark with lust as he stared at my exposed body. I did as I was told, placing my hands on either side of my body, gripping the sheets under me, and biting my lip out of nervous habit.

"Good. Now to reward your behavior…" He stepped back from the bed a little bit to allow me to have a better view. He slowly stripped himself of his shirt, taking care to run his fingertips up his abdomen and slightly brush against his own nipples. He gasped out at the sensation before regaining his composure.

"Next, I want to watch you pleasure yourself. Show me how naughty you are. I know you have thought about me before when you touched yourself." He said as he sat in the desk chair and propped his chin in his hand in a curious manner. I blushed but did not argue at his command.

I moved my stiff hands toward my dripping erect member. I used my fingers to smear the pre-cum down my shaft first, to help lubricate myself. I brought the fingers back up to make teasing circles around my slit. I gasped out at the sensation. I moved my other hand up to tease my nipples, making my dick grow even harder in response.

I looked into Yukio's clouded eyes as he watched my every motion. I grabbed myself roughly and started to pump my dick. I couldn't hold back the moans that flew from my mouth. I could see Yukio biting his lip, as to keep himself from intervening. In retort, I used the hand occupying my nipples to come up to my mouth. I took several fingers in it at once, sucking in a sloppy manner. I could feel drool coming out the sides. I watched as Yukio gently rubbed the hardness through his pants. It made my mind more clouded in the process.

Next, I stopped my pumping motions to use that hand in assisting my next move. My hands descended to my bottom, and I spread the cheeks apart for Yukio to see from his sitting position across the room. I used one of the slick fingers to circle my entrance before lightly pushing inside. "Nngh… Yukio… So tight!" I screamed.

I could see Yukio palming himself roughing now, becoming more desperate, like myself. When I used my finger to start going in and out of my hole, Yukio stood up and began to strip off the remaining clothes he had on. When he was done and I laid eyes on his beautiful, thick, hard dick that rested in between two creamy, muscular thighs, I was quick to add another finger into my entrance. I knew I needed to be well prepared for what I wanted him to do to me.

As I scissored and stretched my hole, I could hear Yukio gasp as he pumped himself in the same rhythm. I wrapped my tail around my dick to pull at it as I watched him touch himself. It felt incredible having both areas of my body stimulated at the same time.

"Fuck, Rin… How did you learn how to do that? God you look so fucking perfect like that." He said. I could tell he was struggling to contain himself as much as I was.

"Please, brother… I want you inside me." I said as I lifted my hips to let him see how wet and ready I was for him. It didn't take long to feel the weight of his body over me, and his hands replacing my own. He forced my hands out just to have his fingers move in and out.

"I thought you were never going to ask." He said. He quickly withdrew his fingers from my dripping hole, and I heard a squirting sound next. I spread my legs more to see him coating his dick with some sort of lubricant. So, that must have been what he was hiding in the drawer of his desk.

"Are you ready?" He asked. I nodded my head feverishly, prodding my hips against him to show just how much I couldn't wait anymore. I draped my tail around his legs to hold him closer. In response, he did not hesitate to thrust himself all the way inside of me in one motion. My legs wrapped around his waist to hold him still while I adjusted to the girth.

"Yu-yukio. Feel so good..." I gasped out. He answered with another mind-blowing kiss to distract me from the pressure. I moaned in my brother's mouth and used my hands to do what they have been itching for since this all began.

I traced my hands down his back to the base of his tail. I lightly brushed the hair and curled my finger around it. The reaction was beautiful. Yukio threw his head back in a throaty moan and pounded into me in an unforgiving pace. "Fuck! What is that?" He said in my ear, biting at the shell as he continued to thrust in and out.

"I… just touched" _**thrust**_

"Your demon" _**thrust**_

"Dick!" I screamed, barely coherent. I was so pleased to know that even my brother had a weak spot.

Suddenly, Yukio pulled out of me. I opened my eyes wide in shock and slight anger that he stopped. I didn't have time to say anything before Yukio flipped me over on my hands and knees to reenter me at a different angle. He bit down on my neck before harshly saying, "Let's see how you like it…"

At the same moment his member found my prostate, his hand also found my tail. He twirled his fingers around it tenderly, while his cock roughly pounded my prostate in sync. It made my eyes see a blinding white light. I pushed back, meeting my brother's cruel thrusts. I screamed out Yukio's name, unable to contain the pleasure I was feeling in the moment.

"God, Rin. You are so tight you are practically sucking me in deeper. I want to fuck you so hard that you won't be able to move for days when I'm done with your ass." He said, going even harder.

Between the dirty talk, tail touching, and prostate pounding, I couldn't hold back anymore. "Yukio! I can't.." I gasped out.

"Me too. Cum with me." He said.

I felt a numbing sensation take over my body before it convulsed, my dick unleashing string after string of cum onto the bed below me. I could feel a warm heat travel up my back into the pit of my stomach as Yukio came inside me. I moaned again as Yukio felt impossibly bigger inside of me at that time. I felt him collapse on my back, which made me fall limply onto the bed.

"Fuck, Rin… I can't get used to this knotting thing." He panted out.

"Huh?" I said trying to catch my breath and regain my strength.

"Alphas have a knot when they cum. It means the base of my dick swells, and basically I am stuck inside of you until it lets down." He replied. I could feel him licking the sweat that gathered around my neck.

"Mmm..." I acknowledged, thrusting back gently against the dick still buried inside of me. My numb mind could barely process anything other than the body latched to mine. I could feel the stirring of arousal returning already.

"You are such a good Beta, brother. I can't wait on all the fun we get to have now that we are mates. Just don't flare up, if you don't want to get pregnant." He said as he already began trying to thrust his still swollen member deeper inside of me.

I don't really know what all he is talking about right now, but it can wait for another day. I was too focused on fucking to care about anything else right now.

 _Please R &R!_


End file.
